Pollen cryopreservation of bitter gourd (Momordica charantia) – An emerging technology for plant breeding and conservation

Pollen cryopreservation of bitter gourd (Momordica charantia) – An emerging technology for plant breeding and conservation Anilkumar G S1 and P E Rajasekharan2 1 – Research Fellow, Division of Flower and Medicinal Crops, ICAR - IIHR, Bangalore, India 2 – Principal Scientist, Division of Flower and Medicinal Crops, ICAR - IIHR, Bangalore, India Corresponding author mail – anilkumargs14@gmail.com Abstract: Pollen cryopreservation is an important tool for the maintenance of male gametes and can promote improved efficiency in breeding and germplasm conservation and exchange. Previous studies in Momordica genus reported the threat of genetic erosion to a great extent. Hence, storing pollen for future use is an important tool in this genusin conserving genetic diversity. The success of pollen storage for genetic conservation purposes depends on many factors, and it is essential that the chosen procedure will ensure maintenance of high genetic integrity, vigour and germination profiles. Thus, it is essential to evaluate pollen viability before, during and after long-term conservation. In this context, a study was conducted at Division of Flower and Medicinal crops, ICAR-IIHR, Bengaluru to check the pollen viability and feasibility of cryopreservation in Momordica charantia. The flowers buds are bagged one day prior to opening and collected in the next morning at peak anthesis time (7:00 am). The pollen are extracted using camlin paint brush and collected in butter paper and kept for drying in desiccator to reduce the moisture of pollen. Viability by in-vitro germination assessment was carried by hanging drop technique using Brew-bakers media containing different concentrations (10, 15, 20 and 25 per cent) of sucrose solution. Followed by the fresh pollen were packed in butter paper covers enclosed in sealed aluminum pouches which were rapidly plunged into the cryobiological system containing liquid nitrogen. Post cryopreservation germination test was carried out after one week to check the germination ability of pollen. The fresh pollens recorded maximum germination percentage of 78.25 % and it was 72.50 % after one week of cryopreservation with 10 % of sucrose in Brew-bakers media. The results indicate that, there was a variable response to the germination of cryopreserved pollen and these observations ascertained thatM. charantia pollen can be recovered viably after cryogenic storage in various proportions. It is our understanding that pollen cryopreservation is a safe and practical alternative for conserving nuclear genetic variability that is often neglected by potential users. This technique has the potential to overcome challenges of breeding programs, such as flowering asynchrony between different parent genotypes, and the production of insufficient pollen in nature. It alsofinds its commercial importance in hybrid seed production by providing the viable pollen for primary and supplementary pollination during offseason. Key words: Cryopreservation, In-vitro germination, Momordica charantia, Brew-bakers media